diff --git a/libcontainer/cgroups/fs/cpu.go b/libcontainer/cgroups/fs/cpu.go index 31c1c874e..7ca8b8a8d 100644 --- a/libcontainer/cgroups/fs/cpu.go +++ b/libcontainer/cgroups/fs/cpu.go @@ -4,6 +4,7 @@ package fs import ( "bufio" + "errors" "fmt" "os" "strconv" @@ -11,6 +12,7 @@ import ( "github.com/opencontainers/runc/libcontainer/cgroups" "github.com/opencontainers/runc/libcontainer/cgroups/fscommon" "github.com/opencontainers/runc/libcontainer/configs" + "golang.org/x/sys/unix" ) type CpuGroup struct{} @@ -71,15 +73,33 @@ func (s *CpuGroup) Set(path string, r *configs.Resources) error { return fmt.Errorf("the minimum allowed cpu-shares is %d", sharesRead) } } + + var period string if r.CpuPeriod != 0 { - if err := cgroups.WriteFile(path, "cpu.cfs_period_us", strconv.FormatUint(r.CpuPeriod, 10)); err != nil { - return err + period = strconv.FormatUint(r.CpuPeriod, 10) + if err := cgroups.WriteFile(path, "cpu.cfs_period_us", period); err != nil { + // Sometimes when the period to be set is smaller + // than the current one, it is rejected by the kernel + // (EINVAL) as old_quota/new_period exceeds the parent + // cgroup quota limit. If this happens and the quota is + // going to be set, ignore the error for now and retry + // after setting the quota. + if !errors.Is(err, unix.EINVAL) || r.CpuQuota == 0 { + return err + } + } else { + period = "" } } if r.CpuQuota != 0 { if err := cgroups.WriteFile(path, "cpu.cfs_quota_us", strconv.FormatInt(r.CpuQuota, 10)); err != nil { return err } + if period != "" { + if err := cgroups.WriteFile(path, "cpu.cfs_period_us", period); err != nil { + return err + } + } } return s.SetRtSched(path, r) } diff --git a/tests/integration/update.bats b/tests/integration/update.bats index 2004d9efc..b9a5b602c 100644 --- a/tests/integration/update.bats +++ b/tests/integration/update.bats @@ -345,6 +345,15 @@ EOF check_cpu_quota -1 1000000 "infinity" } +@test "set cpu period with no quota (invalid period)" { + [[ "$ROOTLESS" -ne 0 ]] && requires rootless_cgroup + + update_config '.linux.resources.cpu |= { "period": 100 }' + + runc run -d --console-socket "$CONSOLE_SOCKET" test_update + [ "$status" -eq 1 ] +} + @test "set cpu quota with no period" { [[ "$ROOTLESS" -ne 0 ]] && requires rootless_cgroup